1. Field of the Invention
The present invention relates to a cabinet installed outdoors in a hermetic state and realizing heat radiation of devices contained therein, and to a heat radiation member.
2. Description of the Related Art
Recent years have seen a rapid increase in the number of portable type terminals accessing a mobile communication system, so that a radio base station apparatus forming a wireless zone in such a mobile communication system has been demanded for downsizing as well as increasing transmission power.
The downsizing and the increasing of the transmission power are technically contradictory demands, however, in case of installing the radio base station apparatus in a residential area, severe demands for reduction of noises imposes great restrictions on thermal design and mounting of the radio base station apparatus.
For a prior art technique for heat radiation realizing both of the downsizing of and increasing of the transmission power of the radio base station apparatus, for example, promotion of heat radiation according to a forced air cooling using a heat pipe is disclosed in the following References 1 to 3.
[Reference 1] Japanese Unexamined Patent Application Publication No. Hei 6-235591 (Abstract)
[Reference 2] Japanese Unexamined Patent Application Publication No. Hei 7-83582 (Abstract)
[Reference 3] Japanese Unexamined Patent Application Publication No. Hei 7-113588 (Abstract)
All of the abovementioned prior arts, however, entail high costs and do not always achieve sufficiently high total reliability because fans used for forced air cooling generate a lot of noise and need to be exchanged for maintenance. Here, it is not necessary to exchange the fans if the heat radiation is sufficient by a natural air cooling.
However, the natural air cooling is good for radiation of heat of small quantity, and it works only when a radiator has a sufficiently large heat radiation area. Besides, the increase in the heat radiation area leads to prevention of the downsizing of the radio base station apparatus, so that in reality, it is difficult to apply the natural air cooling to the radio base station apparatus whose essential portions are contained inside a hermetic cabinet so as not to be weather-beaten outdoors.